Switch-latching mechanism.



E. H. JACOBS.

SWITCH LATCHING MECHANISM.

APPLICATION FILED AUG.19,1911.

1,126,221 v Patented Jan.26, 1915.

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E. H. JACOBS. SWITCH LATGHING MECHANISM.

APPLICATION FILED 10119, 1911.

Patented Jan. 26, 1915.

2 SHEETS-SHEET 2.

INVENTDRI ERNEET HJAEDEJE,

Hi: ATTURNEZY.

UNITED STATES PATENT OFFICE.

ERNEST H. JACOBS, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

SWITGH-LATCHING MECHANISM.

Application filed August 19, 1911.

To all whom it may concern:

Be it known that I, ERNEST H. JACOBS, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Switch-Latching Mechanism, of which the following is a specification.

My invention relates to electric switches which are locked closed and also locked open, and more particularly to motor driven switch actuating mechanisms in which a rotatable actuating shaft connected to move the switch contacts is stopped and held at the proper points in its rotation by some suitable form of stop or lock which catches and stops the shaft when the switch is fully closed and also when it is fully open. Switches of this type are usually so constructed that the stop will be pushed out of the way and the switch released unless the stop is held by some suitable form of latching mechanism. An electroresponsive device, such as a solenoid, ordinarily controls the latching mechanism and upon overload or other abnormal condition in the circuit trips the latching mechanism and thereby permits the stop to move, whereupon theswitch opens automatically. In the course of time rust and dirt may accumulate on the latching mechanism and the oil may become so gummy or sticky that the latching mechanism is sluggish, and does not permit the stop to return to its normal position in time to engage the actuating member and stop the switch or else does not hold the stop firmly. In either case the switch continues to open and close or pump instead of making one complete stroke and then stopping.

The object of my invention is to provide a switch which does not pump, but makes only one stroke either in opening or closing. In accordance with my invention I positively stop and hold the switch in either the closed or the open position, regardless of friction in the latching mechanism or sluggishness of the stop in returning to engaging position by forcibly returning the stop to its normal position, where is is ready to engage and hold the switch mechanism before the switch mechanism has completed either its opening or its closing movement. In the preferred arrangement the latching mechanism for controlling the stop Specification ofLetters Patent.

Patented Jan. 26, 1915.

Serial No. 644,972.

is mechanically and positively set by the movement of the switch mechanism to hold the stop in normal position, so that continuous opening and closing or pumping of the switch cannot occur.

My invention will best be understood in connection with the accompanying drawings which merely for purposes of illustration show one of the various forms in which the invention may be embodied and in which Figure l is a view in elevation of one form of switch actuating mechanism embodying my invention; and Figs. 2 and 3 are views partly in elevation and partly in section on an enlarged scale of the latchingmechanism for controlling the stop. The particular form of switch shown in the drawings comprises a fireproof cell which contains the contacts and comprises walls 1 and a cover or. top 2 of some suitable insulating material such as soapstone. The movable contacts 3 are mounted on a vertically movable actuating rod 1 ofwood or other suitable insulating material passing through the cover or top 2 and having its upper end connected to a parallel motion actuating mechanism mounted on the top or cover 2. The switch shown is illustrated in detail in U. S. Patent 843,070, Button, Feb. 5, 1907, and it is sufficient in this case to note that the parallel motion mechanism comprises an arm 5 for moving the actuating rod 4, a link 6 pivoted upon a rock shaft 7, a link 8, a lever 9, and a guide link 10, all pivotally connected and so pr0- portioned that the outer end of the arm 5 moves substantially in a straight line.

The closing movement of the switch is assisted by a spring 11 engaged and compressed by the free end of the lever 9 near the end of the opening movement of the switch. A similar spring, not shown, is compressed by the lever 9 as the switch completes its closing movement. These springs will throw the switch into a position about half way between open and closed position unless the switch mechanism is positively locked and held in its open position and also in its closed position.

The parallel motion mechanism is actuated from any suitable source of power,

preferably through a connecting rod 12 connected at one end to the lever 9 and at the other end to a crank 13 mounted on a rotatable actuating member or shaft 14. A gear wheel 15 loosely mounted on the shaft 14 meshes with a pinion 16 which in turn'is driven by a motor 17 through worm gearing not shown in the drawing. .Between the gear wheel 15 and the shaft 14 is a clutch which locks the gear wheel to the shaft when the gear wheel runs faster than the shaft but which permits the shaft to outrun the gear wheel. When the switch is either fully open or fully closed the crank 13 is slightly over center, one or the other of the springs 11 is compressed, and the switch will move unless locked or stopped. When either open or closed the switch is looked through that clutch member which is secured to the shaft 14 inside the gear wheel 15 and is provided with holding arms or dogs 18 rigidly mounted in a position to engage and be held by a stop 19. In the preferred construction the stop as best shown in Figs. 2 and 3 is made in the form of a bell crank loosely mounted upon the rock shaft 7, and is provided with a roller 20 which engages the arms 18. The stop is biased to its normal engaging position by a spring 21. The arms 18 will push the stop 19 out of the way in spite of the spring 21 unless the stop is held rigid by some suitable form of latching mechanism.

The switch shown in the drawings is made automatically responsive to abnormal conditions on the circuit. by some suitable latching mechanism which controls the stop 19 and in turn is released by some electroresponsive device, such as an overload coil 22, preferably secured to the framework. The latching mechanism may become sluggish and stiff, and then does not permit the stop to return to its normal position in time to catch and hold the shaft 14 at the proper point in its rotation, or else does not hold the stop firmly enough to stop and hold the switch. 7

In accordance with my invention, sluggishness and stiffness of the latching mech-' anism is overcome by causing some movable member of the actuating mechanism, preferably the actuating shaft 14, to force the latching mechanism into latching or holding position during the first quarter revolution of the actuating shaft 14. The stop 19 is controlled by a normally positive yet collapsible latching mechanism consisting of a latching toggle slightly underset and held 7 against collapse by a latch which in turn is controlled by the overload coil. The form of latching toggle which I prefer comprises two links 23 and 24, connected to one arm of the stop 19 and to an adjacent stationary.

abutment. This toggle is forcibly straightened during the movement of the switch by any suitable connections between the toggle and the switch mechanism. In the particu-',, lar arrangement shown the link 23 has an extension 25, which is positively lifted until the toggle is nearly straight by cams 26, which may be placed on any movable part of the mechanism, but are preferably fixed to and rotate with the actuating shaft 14. The other l1nk24 of the toggle has an extension 27, and the latching toggle is held against collapse by a latch 28 which is mounted on,

vided with a tail 29 which extends along beneath the link 24'of the toggle and immediately below it to such a distance that the core 30 of the overload coil engages the tail 29. There is suflicient clearance between the tail 29 and the link 24 to permit the core to raise the tail 29 and cause the latch to release the extension 27 of the link, and as the core rises further it brings the tail 29 against the pivot of the toggle and exerts a direct force tending to collapse the toggle. As the collapsed toggle is straightened out by being forced down into the normal position shown in Figs. 1 and 3 the descending link 24 engages and forces down the tail of the latch and swings the latch toward latching position. By the time the toggle is straight the latch is almost touching the extension 27 and is sure to catch the extension and thereby hold the toggle in its normal noncollapsed position.

' When the toggle 23, 24 collapses the move- .ment of the stop- 19 is graduall and easily checked by a buffer 31 mo'unte in the arm of the stop.

The operation of the device is as follows: When an overload occurs in the circuit the core of the overload coil lifts, first causing the latch 28 to release the extension 27 of the latching toggle and then forcing up the toggle until the latching toggle collapses whereupon the arm 18 forces the stop 19 out of the way, and the actuating member or shaft 14 begins to rotate in a counterclockwise direction. A half revolution of the actuating shaft is suflicient to move the switch from the fully closed to the full open position, but by the time the sha t has made one quarter of a revolution one of the cams 26 has engaged the extension of the toggle link 23 and begins to force the toggle into the normal position shown in Fig. 3, at the same time positively forcing the stop 19 back into normal position where it will engage the arms 18. As the toggle is straightened out by the positive action of the cam 26 the tail 29 of the latch is also engaged by the descending links of erations are all completed and the latching mechanism and the stop 19 are in normal position before the actuating member or shaft 14 completes its half revolution, con

sequently the stop 19 is sure to catch and hold the arm 18 when the switch completes its opening movement.

My invention may be embodied'in many other forms than that shown and described and I therefore do not wish to limit myself to the precise arrangement disclosed but aim in the appended claims to cover all modifications with'in'the spirit and scope of my invention.

What I claimasnew and desire to secure by Letters Patent of the United States, is,

5 i l. A switch actuating mechanism comrising a rotatable actuating member, a-

.stop for holding said member at different points in its travel, and biased by the pressure of the actuating member to move out 20 of engaging position to release said member, restraining means normally holding said stop in engaging position, a tripping device to release said restraining means, and means whereby said actuating mechanism during the movement of said member from one point to the next positively returns the said stop to engaging position and said restraining means to normal position.

2. An electric switch comprising actuating mechanism having movable members, a stop for engaging a member of said mechanism to hold it stationary at a predetermined point in its movement, a normally positive collapsible latching mechanism for holding said stop in engaging osition, electroresponsive means for col apsing said latching mechanism and thereby releasing said actuating mechanism, and means whereby said actuating mechanism durin its movement when released forces said latching mechanism into noncollapsed position and returns said stop to engaging position.

3. In an electric switch the combination of an actuating mechanism having movable members, a stop for engaging a member of said actuating mechanism to hold it stationary atapredetermied point in its movement, a toggle for controlling the position of said stop and for holding said stop in engaging position when said toggle is extended, means for collapsing said toggle, and connections between said toggle and said actuating mechanism whereby said 55 mechanism during its movement resets said toggle.

4. In an electric switch actuating mechanism comprising movable members, a stop for engaging one of said members to hold it stationary at a predetermined point in its movement, a two-link toggle connected to said stop to hold it in engaging position when said toggle is straight, one of the links of said toggle having a rojection thereon, and a cam on one of sai movable 'members to" engage said projection and tion comprising a toggle which resists the straim-exerted-by said member when said toggle is straight, electroresponsive means for collapsing said toggle to release said member, andconnections between said mechanism and said toggle whereby said member forcibly straightens said toggle during the movement of said member after its release. HGi-A- switch actuating mechanism comprising a rotatable actuating member, a stop for engaging said member to hold it stationary at different points in its revolution, said stop bein normally in engaging position and mova le out of said position to release said member, and connections whereby said mechanism forcibly resets said stop in engaging position while said actuating member is rotating from one position to the next.

7. An electric switch com rising a rotatable contact actuating mem er, a stop for holding said member stationary, restraining means for normally holding said stop in engagin g position, electroresp onsive means cooperating with said restraining means to release sai stop and thereby permit said actuating member to ush said stop out of the way, a cam on said actuating member, and connections between said cam and said restraining means whereby said shaft during a portion of its rotation forces said stop into normal position.

8. In an electric switch actuating mechanism com rising movable members, a stop for engaging one of said members to hold it stationary at predetermined points, a twolink toggle connected to said stop to hold said stop in engaging position, a latch for engaging one of the links of the toggle to hold said toggle extended and having a portion engaged by one of said links whereby said latch is forced into latching position by said link as said toggle is straightened, and means whereby one of said movable members mechanically straightens said toggle while said mechanism is moving.

9. In a switch actuating mechanism, the combination with a movable actuating member, of a normally positive collapsible latching mechanism for said member comprising a holding link for resisting the thrust of said actuatin member, and a latch for en'- gaging said link to hold said mechanism in non-collapsed position, said latch bein forcedtoward latching position by said link as said mechanism moves into non-collapsed position.

ber, of a normally positive collapsible latching mechanism forsaid member comprising a toggle, an electroresponsive device having an armature for collapsing said toggle, :1

latch for normally holding said toggle extended, and a tail on said latch extending into alinement with said armature and between said armature and said toggle, whereby said toggle in straightening engages said tail and forces said latch toward latching position.

In witness whereof, I have hereunto set my hand this 17th day of August 1911,

ERNEST H. JACOBS.

Witnesses:

BENJAMIN B. HULL, 1' HELEN ORFORD. 

